Self-Illuminating Triggered Release of Therapeutics from Photocleavable Nanoprodrug for the Targeted Treatment of Breast Cancer

"Three birds, one stone" strategy of NIR-responsive CO/H2S dual-gas Nanogenerator for efficient treatment of osteoporosis

Osteoporosis (OP), the most prevalent bone degenerative disease, has become a significant public health challenge globally. Current therapies primarily target inhibiting osteoclast activity or stimulating osteoblast activation, but their effectiveness remains suboptimal. This paper introduced a "three birds, one stone" therapeutic approach for osteoporosis, employing upconversion nanoparticles (UCNPs) to create a dual-gas storage nanoplatform (UZPA-CP) targeting bone tissues, capable of concurrently generating carbon monoxide (CO) and hydrogen sulfide (H2S). Through the precise modulation of 808 nm near-infrared (NIR) light, the platform could effectively control the release of CO and H2S in the OP microenvironment, and realize the effective combination of promoting osteogenesis, inhibiting osteoclast activity, and improving the immune microenvironment to achieve the therapeutic effect of OP. High-throughput sequencing results further confirmed the remarkable effectiveness of the nanoplatform in inhibiting apoptosis, modulating inflammatory response, inhibiting osteoclast differentiation and regulating multiple immune signaling pathways. The gas storage nanoplatform not only optimized the OP microenvironment with the assistance of NIR, but also restored the balance between osteoblasts and osteoclasts. This comprehensive therapeutic strategy focused on improving the bone microenvironment, promoting osteogenesis and inhibiting osteoclast activity provides an ideal new solution for the treatment of metabolic bone diseases.

DNA response element-based smart drug delivery systems for precise drug release

Smart drug delivery systems (DDSs) that respond to, interact with, or are actuated by biological signals or pathological abnormalities (e.g., the tumor microenvironment) for controllable drug release are appealing therapeutic platforms for cancer treatment. Owing to their inherent self-assembled nature, nucleic acids have emerged as programmable materials for the development of multifunctional structures. In response to external environmental stimuli, DNA response elements can serve as switches to trigger conformational changes in DNA structures. Their stimulus-responsive properties make them promising candidates for constructing smart DDSs, and advancements in DNA response element-based DDSs in the field of biomedicine have been made. This review summarizes different types of DNA response elements, including DNA aptamers, DNAzymes, disulfide bond-modified DNA, pH-responsive DNA motifs, and photocleavable DNA building blocks, and highlights the advancements in DNA response element-based smart DDSs for precise drug release. Finally, future challenges and perspectives in this field are discussed.

Phytic acid-modified manganese dioxide nanoparticles oligomer for magnetic resonance imaging and targeting therapy of osteosarcoma

Osteosarcoma is the most common malignant tumor in the skeletal system with high mortality. Phytic acid (PA) is a natural compound extracted from plant seeds, which shows certain antitumor activity and good bone targeting ability. To develop a novel theranostics for magnetic resonance imaging (MRI) and targeting therapy of osteosarcoma, we employed PA to modify manganese dioxide nanoparticles (MnO₂@PA NPs) for osteosarcoma treatment. The MnO₂ NPs oligomer was formed by PA modification with uniformed size distribution and negative zeta potential. Fourier-transform infrared spectroscopy, X-ray diffraction, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis demonstrated that PA has been successfully modified on MnO₂ NPs, and the structure of MnO₂@PA NPs is amorphous. In vitro experiments demonstrated that MnO₂@PA NPs oligomer can be efficiently internalized by tumor cell, and the internalized NPs can react with H₂O₂ under acid microenvironment to produce Mn²⁺ and O₂. In vivo experiments demonstrated that MnO₂@PA NPs oligomer can passively accumulate in tumor tissue, and the accumulated NPs can produce Mn²⁺ and O₂ for MRI and targeting therapy of osteosarcoma. In conclusion, we prepared a novel bone-targeting nano theranostics for MRI and therapy of osteosarcoma.

Docetaxel-loaded pH/ROS dual-responsive nanoparticles with self-supplied ROS for inhibiting metastasis and enhancing immunotherapy of breast cancer

BACKGROUND

Although stimuli-responsive nanoplatforms were developed to deliver immunogenic cell death (ICD) inducers to enhance cancer immunotherapy, the complete release of ICD inducers into the tumor microenvironment (TME) was limited by the inadequate supplementation of endogenous stimulus (e.g., reactive oxygen species (ROS)). To address this issue, we synthesized a self-responsive nanomaterial with self-supplied ROS, which mainly consists of a ROS responsive moiety HPAP and cinnamaldehyde (CA) as the ROS-generating agent. The endogenous ROS can accelerate the degradation of HPAP in materials to release docetaxel (DTX, an ICD inducer). In intracellular acidic environment, the pH-sensitive acetal was cleaved to release CA. The released CA in turn induces the generation of more ROS through mitochondrial damage, resulting in amplified DTX release. Using this self-cycling and self-responsive nanomaterial as a carrier, DTX-loaded pH/ROS dual-responsive nanoparticles (DTX/FA-CA-Oxi-αCD NPs) were fabricated and evaluated in vitro and in vivo.

RESULTS

In vitro experiments validated that the NPs could be effectively internalized by FA-overexpressed cells and completely release DTX in acidic and ROS microenvironments to induce ICD effect. These NPs significantly blocked 4T1 cell migration and decreased cell invasion. In vivo experiments demonstrated that the tumor-targeted NPs significantly inhibited tumor growth and blocked tumor metastasis. More importantly, these NPs significantly improved immunotherapy through triggering effector T-cell activation and relieving the immunosuppressive state of the TME.

CONCLUSIONS

Our results demonstrated that DTX/FA-CA-Oxi-αCD NPs displayed great potential in preventing tumor metastasis, inhibiting tumor growth, and improving the efficacy of anti-PD-1antibody.

Cyclic RGD-Functionalized pH/ROS Dual-Responsive Nanoparticle for Targeted Breast Cancer Therapy

Breast cancer is the most common malignant tumor in women and is a big challenge to clinical treatment due to the high morbidity and mortality. The pH/ROS dual-responsive nanoplatforms may be an effective way to significantly improve the therapeutic efficacy of breast cancer. Herein, we report a docetaxel (DTX)-loaded pH/ROS-responsive NP that could achieve active targeting of cancer cells and selective and complete drug release for effective drug delivery. The pH/ROS-responsive NPs were fabricated using nanocarriers that consist of an ROS-responsive moiety (4-hydroxymethylphenylboronic acid pinacol ester, HPAP), cinnamaldehyde (CA, an aldehyde organic compound with anticancer activities) and cyclodextrin (α-CD). The NPs were loaded with DTX, modified with a tumor-penetration peptide (circular RGD, cRGD) and named DTX/RGD NPs. The cRGD could promote DTX/RGD NPs penetration into deep tumor tissue and specifically target cancer cells. After internalization by cancer cells through receptor-mediated endocytosis, the pH-responsive acetal was cleaved to release CA in the lysosomal acidic environment. Meanwhile, the high ROS in tumor cells induced the disassembly of NPs with complete release of DTX. In vitro cellular assays verified that DTX/RGD NPs could be effectively internalized by 4T1 cells, obviously inducing apoptosis, blocking the cell cycle of 4T1 cells and consequently, killing tumor cells. In vivo animal experiments demonstrated that the NPs could target to the tumor sites and significantly inhibit the tumor growth in 4T1 breast cancer mice. Both in vitro and in vivo investigations demonstrated that DTX/RGD NPs could significantly improve the antitumor effect compared to free DTX. Thus, the DTX/RGD NPs provide a promising strategy for enhancing drug delivery and cancer therapy.

Polymeric Dendrimers as Nanocarrier Vectors for Neurotheranostics

Dendrimers are polymers with well-defined 3D branched structures that are vastly utilized in various neurotheranostics and biomedical applications, particularly as nanocarrier vectors. Imaging agents can be loaded into dendrimers to improve the accuracy of diagnostic imaging processes. Likewise, combining pharmaceutical agents and anticancer drugs with dendrimers can enhance their solubility, biocompatibility, and efficiency. Practically, by modifying ligands on the surface of dendrimers, effective therapeutic and diagnostic platforms can be constructed and implemented for targeted delivery. Dendrimer-based nanocarriers also show great potential in gene delivery. Since enzymes can degrade genetic materials during their blood circulation, dendrimers exhibit promising packaging and delivery alternatives, particularly for central nervous system (CNS) treatments. The DNA and RNA encapsulated in dendrimers represented by polyamidoamine that are used for targeted brain delivery, via chemical-structural adjustments and appropriate generation, significantly improve the correlation between transfection efficiency and cytotoxicity. This article reports a comprehensive review of dendrimers' structures, synthesis processes, and biological applications. Recent progress in diagnostic imaging processes and therapeutic applications for cancers and other CNS diseases are presented. Potential challenges and future directions in the development of dendrimers, which provide the theoretical basis for their broader applications in healthcare, are also discussed.

Advances in the Structural Strategies of the Self-Assembly of Photoresponsive Supramolecular Systems

Photosensitive supramolecular systems have garnered attention due to their potential to catalyze highly specific tasks through structural changes triggered by a light stimulus. The tunability of their chemical structure and charge transfer properties provides opportunities for designing and developing smart materials for multidisciplinary applications. This review focuses on the approaches reported in the literature for tailoring properties of the photosensitive supramolecular systems, including MOFs, MOPs, and HOFs. We discuss relevant aspects regarding their chemical structure, action mechanisms, design principles, applications, and future perspectives.